The present invention relates to a novel hydrazone compound, and also relates to a photosensitive material using such a compound.
As a photosensitive material in an image forming apparatus such as an electrophotographic copying apparatus, a printer or a facsimile, there has recently and widely been used an organic photosensitive material which is excellent in machinability and advantageous in production cost and which offers a great degree of freedom for design of performance.
For forming a copied image with the use of an electrophotosensitive material, the Carlson process is widely used. The Carlson process comprises the steps of uniformly charging a photosensitive material with electricity by corona discharge, exposing the charged photosensitive material to a document image, thereby to form an electrostatic latent image corresponding to the document image, developing the electrostatic latent image by a toner containing developer, thereby to form a toner image, transferring the toner image to a medium such as paper, fixing the toner image transferred to the medium, and cleaning the photosensitive material to remove toner remaining thereon after the toner image has been transferred. To form an image of high quality in the Carlson process, it is required that the electrophotosensitive material is excellent in charging and photosensitive characteristics and presents a low residual potential after exposed to light.
Conventionally, there have been known inorganic photoconductive materials such as selenium, cadmium sulfide and the like as electrophotosensitive materials. However, these inorganic photoconductive materials are toxic and need great production costs.
There has been proposed a so-called organic electrophotosensitive material using various organic substances in place of the above-mentioned inorganic substances. Such an organic photosensitive material has a photosensitive layer comprised of an electric charge generating material for generating electric charges by light exposure and an electric charge transferring material having a function of transferring the electric charges thus generated.
To meet various requirements for the organic electrophotosensitive material, it is necessary to properly select the electric charge generating material and the electric charge transferring material. As the electric charge transferring material, various organic compounds have been proposed and put on the market. By way of example, a hydrazone compound represented by the following formula (x) serving as the electric transferring material has been disclosed in Japanese Unexamined Patent Publication No. 272571/1990. ##STR3## (wherein A.sup.1 and A.sup.2 are the same as or different from each other and each is a lower alkyl group, a benzyl group or a phenyl group, or they may be bonded to each other, thereby to form a heterocycle together with adjacent nitrogen atoms.)
Referring to the electric charge transferring material according to the prior art, however, sensitivity and repeat characteristics are not sufficient.